In 1928, along with Wernher von Braun, Rolf Engel joined the newly formed Berlin Section of the Verein Für Raumschiffahrt (German Rocket Society), where he participated in liquid propellant rocket experiments at the Raketenflugplatz (Rocket Airfield) with people like Rudolf Nebel, Willy Ley, Klaus Riedel and von Braun. Engel also worked as chief technical assistant to Johannes Winkler, who launched the HW-1 rocket on February 20, 1931 at a military parade ground near Dessau. This event represented the first launching of a liquid propellant rocket by someone other than Robert Goddard. This collection consists of files for eight different projects related to rockets conceived by members of the Verein für Raumschiffahrt, including Hermann Oberth, Rudolf Nebel, Franz Mengering, Reinhold Tiling, Johannes Winkler and some unattributed work.

Rolf Engel was born on August 10, 1912 in Menz/Ruppin, Germany. In 1928, along with Wernher von Braun, Engel joined the newly formed Berlin Section of the Verein Für Raumschiffahrt (German Rocket Society), where he participated in liquid propellant rocket experiments at the Raketenflugplatz (Rocket Airfield) with people like Rudolf Nebel, Willy Ley, Klaus Riedel and von Braun. Engel also worked as chief technical assistant to Johannes Winkler, who launched the HW-1 rocket on February 20, 1931 at a military parade ground near Dessau. This event represented the first launching of a liquid propellant rocket by someone other than Robert Goddard. From 1932 to 1935, Engel founded two research groups, Research Institute for Rocket Technology and Versuchsabteilung (Experimental Department), but they were short-lived due to lack of funding. In 1939, Engel was named technical director of Versuchsanstalt Für Strahltriebwerke (Research Center for Jet Engines) where work primarily focused on the development of fin-stabilized, solid propellant liquid rockets. During World War II, Engel was a member of the Ministry of Armament's Commissions on Ammunition, Armament, and Ballistic Missiles and also a member of the Reichsforschungsrat (National Research Council). From August 1944 to April 1945, he served as the head of the test division of Waffen-Union Skoda-Brunn in Pibrans, Czechoslovakia. From 1946 to 1952, Engel worked in France as a consultant for ONERA (Office National d'Etudes et de Recherches Aéronautiques). From 1952 to 1957, he worked in Egypt advising the Egyptian Air Force as Director of CERVA (Compagnie des Engines à Réaction pour Vol Accéleré). From 1957 to 1962, Engel lived in Rome, Italy and served as a consultant to various guided missile manufacturers including SISPRE (Societa Italiana per lo Studio della Propulsione a Reazione) and Bombrini Parodi-Delfino. In 1962, Engel returned to Germany where he was named Director of the newly-formed space division of the Messerschmitt-Boelkow-Blohm (MBB) consortium in Munich. In 1971, Engel retired from active professional life for health reasons, although he published several books throughout the 1970s and 1980s. Rolf Engel died in 1993 at the age of 81.